Field of the Invention
The present invention relates to an apparatus that performs fully closed position learning control and fully opened position learning control of an electronically-controlled throttle mounted in an automobile.
Description of the Related Art
Automobiles equipped with an electronically-controlled throttle (hereinafter, also referred to as a throttle) have become widespread. It is known that throttle control is implemented through PID control based on the difference between a desired throttle opening degree and a throttle opening degree detection value. In other words, while monitoring the throttle opening degree sensor detection value, a throttle control apparatus supplies a driving current having a suitable direction and magnitude to a throttle driving motor in a direction in which the difference from the desired throttle opening degree is decreased so that the throttle opening degree detection value coincides with the desired throttle opening degree.
Several kinds of methods are known in which for the purpose of ensuring a throttle opening degree detection value, the mechanical throttle fully closed position is utilized as a reference position and a throttle control apparatus learns (hereinafter, this learning is referred to as fully closed learning and the stored value is referred to as a fully closed learning value) a throttle opening degree sensor detection value at the throttle fully closed position.
Similarly, several kinds of methods are known in which a throttle control apparatus learns (hereinafter, this learning is referred to as fully opened learning and the stored value is referred to as a fully opened learning value) a throttle opening degree sensor detection value at the mechanical throttle fully opened position.
Meanwhile, a method is known in which the fully closed learning and the fully opened learning are implemented during a self-shutoff delay period that is set immediately after the ignition key switch of an automobile has been turned off (for example, refer to Patent Document 1).
In addition, a technology is also known in which in an automobile having an idling stop function, the fully closed learning is implemented during an idling stop period (for example, refer to Patent Document 2).